This invention relates to a composition and method whereby simethicone is prepared as a dry powder by intermixing it with calcium silicate to form a dry, free-flowing powder of less than 50 micron size suitable for oral administration in tablet, capsule or other form as an antigas ingredient or for use as a defoaming processing aid.
Simethicone is a mixture of polydimethylsiloxane and silica gel suitably purified for pharmaceutical use. The preparation of liquid methylsiloxane polymers are delineated in United States Patent No. 2,441,098, the disclosure of which is hereby incorporated by reference. The normal physical state of simethicone is a water-white to grey, translucent, viscous, oil-like liquid with a density of 0.965-0.970 grams/cubic centimeter having demonstrable immiscibility with water and alcohol.
The medically established therapeutic use for simethicone is as an ointment base ingredient, topical drug vehicle and a skin protectant, but most particularly as an antigas and antiflatulent agent for human application, and an antibloating agent for veterinary application.
Various antacid or antigas formulations, some containing simethicone, are disclosed in the prior art, including U.S. Pat. Nos. 4,605,551 to Buehler et al; U.S. Pat. No. 3,326,754 to Prussin et al; U.S. Pat. No. 2,774,710 to Thompson et al; U.S. Pat. No. 4,115,553 to Rubino et al; U.S. Pat. No. 4,396,604 to Mitra; and U.S. Pat. No. 4,581,381 to Morris et al.
The preferred pharmaceutical solid dose delivery system for an antigas and antiflatulent agent such as simethicone is in the form of a chewable tablet. Such chewable tablets often contain antacid ingredients such as calcium carbonate, aluminum hydroxide, magnesium hydroxide, and magnesium carbonate.
It is extremely troublesome to distribute the oil-like, viscous, water and alcohol immiscible simethicone expeditiously and uniformly throughout a tablet granulation prior to compression. It is equally difficult to be certain that simethicone is in a sufficiently divided and dispersed state so that its action will be quick and effective when administered per os as a chewable or swallowable tablet or powder-filled capsule.
Bearing in mind the problems and deficiencies of the prior art, it is therefore an object of the present invention to provide an effective simethicone-containing powder for use in antacid, antigas and/or antiflatulent formulations.
It is another object of the present invention to provide a facile method of producing an effective simethicone-containing powder utilizing conventional equipment at relatively low cost.
It is a further object of the present invention to provide a simethicone-containing powder for use in formulations which, after processing, retain acceptable defoaming activity.
The present invention achieves these objects and satisfies the long felt need to overcome the difficulties in utilizing simethicone in tablet or capsule preparations. A larger amount of simethicone can be incorporated on calcium silicate by the method of this invention than has previously been disclosed in the prior art. The extremely small particle size of the simethicone-containing powder, established as less than 50 microns, makes it possible to have uniform distribution of the simethicone by simple mixing.